Another study finds pregnant women can pass the coronavirus to their fetus, but it's rare

• New research coronavirus may be able to infect fetuses if the pregnant mother has the virus.
• Researchers looked at samples of breast milk, placenta, and umbilical cord blood to see if they could detect the virus.
• The study was done on 31 women in Italy during the outbreak.

A small study in Italy has found evidence suggesting that, in pregnant women, the coronavirus can reach their fetus.

Researchers examined samples of various specimens, like breast milk, placenta, vaginal swabs, amniotic fluid, and umbilical cord blood, from 31 women from three Italian hospitals during the outbreak during March and April 2020, all in their third trimester.

They found signs of the virus and antibodies across the samples — in one vaginal swab, one breast milk sample, one placenta sample, and in nine samples of cord blood.

After weeks of health officials assured the public that vertical transmission wasn't possible, this small study adds more weight to evidence showing the opposite appears to be true.

"Our study shows that vertical transmission in utero from mother to child of COVID-19 is indeed possible," study author Dr. Claudio Fenizia, immunology specialist at the University of Milan, said said at a virtual medical conference.

At the start of the pandemic, experts believed fetuses could not be infected

There was a time when women were told vertical transmission wasn't possible, but a growing body of research is suggesting otherwise.

Three studies that came out in March also suggested that pregnant women could infect fetuses in utero. The studies were small, with sample sizes of a single mother and child, six infants, and 33 infants. None of the infants died.

The studies "suggest to me that the virus can cross the placenta," Sonja Rasmussen, a pediatrician and a professor at the University of Florida, told STAT.

Other infectious diseases, like HIV and Zika, can be passed on to a fetus by a pregnant women.

One of the children in the study was born with COVID-19, doctors said

The newborn children were all tested for coronavirus, and in the case of one child, "there's strong evidence suggesting that the newborn was born already positive because we found the virus in the umbilical cord blood and in the placenta," Fenizia said.

Only two of the 31 newborn children tested positive for COVID-19, making fetal infection relatively rare. Those two children quickly recovered from the virus.

"Generally, children have much less of a chance of having an adverse [COVID-19] outcome, except maybe for newborns," Anthony Fauci, director of National Institute of Allergy and Infectious Diseases, said at the conference.

Uncertainty about the virus is making pregnancy a scary prospect

Researchers still don't know a lot about the health ramifications of having coronavirus while pregnant, which makes pregnancy a scary prospect for many women.

"I'm feeling less in control, more worried, as new data comes in about infected infants and pregnant women," one pregnant woman previously told Business Insider.

"I feel like we don't know enough about this virus; however, what we do know seems to worsen daily," another woman said. "One moment they are saying pregnant women should be OK, then a week later, the UK is recommending pregnant women stay home for three months."